The present invention relates to a semiconductor processing device, and particularly to a technique which is applied effectively to a semiconductor processing device which incorporates an SRAM-type field programmable gate array (FPGA) and a nonvolatile memory such as a flash memory.
A study conducted by the inventors of the present invention has revealed the following trend of technology pertaining to LSI devices such as microcomputers and electronic appliances which incorporate the LSI devices.
In the recent industry of electronic appliances which incorporate microcomputers, there is arising a demand of field programmability which facilitates the alteration and adjustment of microcomputer programs which become necessary throughout the stages of development, prototype manufacturing, preparation of production and large-scale production for the sake of dealing with the increase in the volume of programs, the reduction of product development time, the improvement of performance, and the adjustment of control data. To meet this demand, one-chip microcomputers which incorporate central processing units (CPU) and flash memories are being developed.
The LSI user who constructs a practical system deals with the need of precise tuning of signals and customization, which cannot be done solely by the software alteration in the flash memory, by mounting a field programmable gate array and programmable logic device on a system board and connecting these parts with the LSI on the board. The field programmable gate array and programmable logic device enable the LSI user to realize a logic circuit on the LSI in a very short time based on a high-grade descriptive language and logical drawing.
A technique of mounting an LSI and a field programmable gate array on the user board is described in Japanese Unexamined Patent Publication No. Hei 5(1993)-233844 for example. This patent publication discloses a semiconductor device which includes an SRAM-type field programmable gate array and a PROM which stores data for establishing a logic circuit on the array.